NEW YORK (Reuters Health) - Patients with Child's class A cirrhosis and mild encephalopathy score better on cognitive function tests if they eat breakfast, a new study shows.

At baseline, patients had significantly lower total scores and subscores in 4 of 7 cognitive categories (memory, informed processing speed, attention, and executive functions), compared with age- and gender-matched controls, according to Dr. Nachum Vaisman, of Tel Aviv Sourasky Medical Center, Israel, and colleagues. But when they were re-tested two hours after breakfast, their attention and executive function scores had improved (p = 0.003 and p = 0.04, respectively).

Given these results, along with reports of "high rates of accidents, traffic violations, and fatigue among patients with minimal hepatic encephalopathy," the research team believes all such individuals should be "encouraged to diligently incorporate breakfast into their daily routine," according to the May 5th online report in the American Journal of Clinical Nutrition.

Overall, the study included 21 patients and 21 controls. The researchers randomized subjects in each group to receive a 500-kcal breakfast, or to fast, and they analyzed serum ammonia concentrations and cognitive functions.

Ammonia levels were significantly higher in patients compared to controls (71.8 vs 45.8 mcg/dL). But while patients with the highest ammonia levels had the worst baseline scores, and while ammonia levels rose even higher with breakfast, the patients who ate still had improvements in their cognition.

Among controls, however, those who continued to fast performed better.

The researchers conclude, "Chronic hyperammonemia may negatively affect attention" and "prolonged periods of starvation may be responsible for these changes."